107 St, Maurice and Ci^aiborne PelEcypoda 107 



the natural position indicate that there was a small external ligament in 

 addition to the large internal resilium. 



Locality. — Claiborne, Ala. (sand bed). 



Erycina plicatuia Dall, PI. 37. Figs. 7, 8. 



E. plicatuia Dall, Trans. Wag. ,111, 1900, p. 1143, pl. 44, figs. 7, 12. 



DalPs original description. — Shell compressed, ovate, inequilateral, 

 the anterior side longer ; beaks low, pointed, somewhat prosocoelous ; sur- 

 face near the beaks faintly concentrically striate or smooth ; about half-way 

 to the margin from the umbo the sculpture grows stronger, consisting of 

 fine, low, rather sharp plications, not always continuous nor in exact har- 

 mony with the incremental lines; anterior dorsal margin depressed in front 

 of the beaks, nearly straight for a short distance, then rounding evenly to 

 the anterior end ; base arcuate, posterior end more bluntly rounded, with 

 the posterior dorsal margin arcuate and high, hinge plate narrow, channelled, 

 with a short, obscure anterior lamella, whose "hook" is represented by a 

 small pustular elevation ; posterior lamella long, arcuate, almost fused with 

 the margin but rising distalh' to a small elevation ; interior of the valve 

 smooth or with faint radial lines ; adductor scars narrow, long, extending 

 well down towards the base. I^on. 9.5, alt. 7, diam. 2.2 mm. 



Two left valves of this well-marked species were found in the marl. 

 The other species described from this horizon are much smaller and more 

 inflated, and the young of E. plicatuia, judging by the incremental lines, 

 had a different outline from either of the others. 



Eocene of the Claiborne sands at Claiborne, Ala. 



Erycina whitfieltii Meyer, PI. 37. Fig. 9. 



E. cvhitfieldi Meyer, Bull, i, Geol. Surv. Ala., 18S6, p. 82, pl. i, 

 fig. 29. 



Meyer's original description. — Small ; substance of the shell thin, 

 porcellaneously shining ; oval ; convex ; insequilateral, the anterior side the 

 largest ; left valve with two obsolete pyramidal teeth on the anterior side, 

 and on the posterior side a compressed one, which is very small and dis- 

 tant from the beak; surface shining, smooth, except for very fine concen- 

 tric lines of growth ; margin entire. 



Locality. — Claiborne, Ala. 



The nearest species in the Paris Basin seems to be Erycina obsoleta 

 Desh. 



Bornia scintillata Dall, Pl. 37. Fig. 10. 



B. sciu til lata Dall, Trans. Wag., Ill, 1900, p. 1149, pl. 49, fig. 10. 



DalVs original description. — Shell small, subtrigonal, subequilateral, 

 polished, finely, sharply radially grooved, the grooving of the middle of 

 the disk finer and closer than that towards the ends ; the beaks moderately 



